Antiproteinuric Effects of Green Tea Extract on Tacrolimus-Induced Nephrotoxicity in Mice

Tacrolimus, Cytochrome P450, Interactions with Food Variables in Organ Transplant Recipients; A Current and Comprehensive Review

The well-established calcineurin inhibitor, tacrolimus, as an immunosuppressive agent, is widely prescribed after organ transplantation. Cytochrome P450 (CYP 450) isoforms are responsible for the metabolism of many features associated with food parameters like phytochemicals, juices, and fruits. This review article summarizes the findings of previous studies to help predict the efficacy or side effects of tacrolimus in the presence of food variables. From the commencement of databases associated with the topic of interest to 26 October 2024, all relevant articles were searched through PubMed, Scopus, and Web of Science. The suggested therapeutic range for tacrolimus trough concentration (C0 ) was reported as 5-15 ng/ml blood. Tacrolimus interaction with food variables could significantly change C0 after organ transplantation. For example, grapefruit juice could increase tacrolimus C0 due to CYP enzyme inhibition. Toxicity such as nephrotoxicity could result from turmeric and other herbal or food products. By inhibiting tacrolimus-metabolizing enzymes and transporters, a high intake of vegetables could increase the risk of adverse effects. Secondary metabolites of vegetables could lead to toxicity in patients with tacrolimus. Furthermore, grapefruit juice, citrus fruits, turmeric, and pomegranate juice could change clinical pharmacokinetics parameters such as Tmax, Cmax, AUC, and C0 of tacrolimus after organ transplantation. Bioavailability of tacrolimus might be decreased by induction of the CYP450 system and P-gp efflux pump due to cranberry, rooibos tea, and boldo. Increased inhibitory effect on CYP450 system and/or P-gp efflux pump by grapefruit juice, schisandra, berberine, turmeric, pomegranate juice, pomelo, and ginger could increase bioavailability of tacrolimus. A vigilant immunosuppressive strategy accompanied by scheduled therapeutic drug monitoring is recommended before and after transplant surgery.

Linagliptin ameliorates tacrolimus-induced renal injury: role of Nrf2/HO-1 and HIF-1α/CTGF/PAI-1

BACKGROUND

Tacrolimus (TAC) is a frequently used immunosuppressive medication in organ transplantation. However, its nephrotoxic impact limits its long-term usage. This study aims to investigate the effect of linagliptin (Lina) on TAC-induced renal injury and its underlying mechanisms.

METHODS AND RESULTS

Thirty-two Sprague Dawley rats were treated with TAC (1.5 mg/kg/day, subcutaneously) and/or Lina (5 mg/kg/day, orally) for 4 weeks. Histological examination was conducted, and serum and urinary biomarkers were measured to assess kidney function and integrity. Furthermore, ELISA, Western blot analysis and immunohistochemical assay were employed to determine signaling molecules of oxidative stress, profibrogenic, hypoxic, and apoptotic proteins. Tacrolimus caused renal dysfunction and histological deterioration evidenced by increased serum creatinine, blood urea nitrogen (BUN), urinary cystatin C, and decreased serum albumin as well as elevated tubular injury and interstitial fibrosis scores. Additionally, TAC significantly increased the expression of collagen type-1, alpha-smooth muscle actin (α-SMA), plasminogen activator inhibitor-1 (PAI-1), and transforming growth factor-beta1 (TGF-β1) renal content. Moreover, TAC decreased the expression of nuclear factor erythroid-2-related factor2 (Nrf2), heme oxygenase 1 (HO-1), and mitochondrial superoxide dismutase (SOD2). In addition, TAC increased protein expression of hypoxia-inducible factor1-alpha (HIF-1α), connective tissue growth factor (CTGF), inducible nitric oxide synthase (iNOS), 8-hydroxy-2-deoxyguanosine (8-OHdG), as well as nitric oxide (NO), 4-hydroxynonenal, caspase-3 and Bax renal contents. Furthermore, TAC decreased Bcl-2 renal contents. The Lina administration markedly attenuated these alterations.

CONCLUSION

Lina ameliorated TAC-induced kidney injury through modulation of oxidative stress, hypoxia, and apoptosis related proteins.

Controversial Interactions of Tacrolimus with Dietary Supplements, Herbs and Food

Tacrolimus is an immunosuppressive calcineurin inhibitor used to prevent rejection in allogeneic organ transplant recipients, such as kidney, liver, heart or lung. It is metabolized in the liver, involving the cytochrome P450 (CYP3A4) isoform CYP3A4, and is characterized by a narrow therapeutic window, dose-dependent toxicity and high inter-individual and intra-individual variability. In view of the abovementioned facts, the aim of the study is to present selected interactions between tacrolimus and the commonly used dietary supplements, herbs and food. The review was based on the available scientific literature found in the PubMed, Scopus and Cochrane databases. An increase in the serum concentration of tacrolimus can be caused by CYP3A4 inhibitors, such as grapefruit, pomelo, clementine, pomegranate, ginger and turmeric, revealing the side effects of this drug, particularly nephrotoxicity. In contrast, CYP3A4 inducers, such as St. John’s Wort, may result in a lack of therapeutic effect by reducing the drug concentration. Additionally, the use of Panax ginseng, green tea, Schisandra sphenanthera and melatonin in patients receiving tacrolimus is highly controversial. Therefore, since alternative medicine constitutes an attractive treatment option for patients, modern healthcare should emphasize the potential interactions between herbal medicines and synthetic drugs. In fact, each drug or herbal supplement should be reported by the patient to the physician (concordance) if it is taken in the course of immunosuppressive therapy, since it may affect the pharmacokinetic and pharmacodynamic parameters of other preparations.

Calcineurin Inhibitors Nephrotoxicity Prevention Strategies With Stress on Belatacept-Based Rescue Immunotherapy: A Review of the Current Evidence

BACKGROUND

A traditional narrative review was performed to evaluate clinical studies that have examined the clinical implications, risk factors, and prevention of calcineurin inhibitors (CNIs) nephrotoxicity with stress on a belatacept-based rescue regimen.

METHODS

The Cochrane Library, PubMed/MEDLINE, EBSCO (Academic Search Ultimate), ProQuest (Central), and Excerpta Medical databases and Google scholar were searched using the keywords (CNI AND Nephrotoxicity prevention) OR ("Calcineurin inhibitor" AND Nephrotoxicity) OR (Tacrolimus AND Nephrotoxicity) OR (Ciclosporin AND Nephrotoxicity) OR (cyclosporine AND Nephrotoxicity) OR (Belatacept) OR (CNI Conversion) for the period from 1990 to 2020. Fifty-five related articles and reviews were found.

CONCLUSION

A better understanding of the mechanisms underlying calcineurin inhibitor nephrotoxicity could help in the individualization of therapy for and prevention of CNI nephrotoxicity. Identification of high-risk patients for CNI nephrotoxicity before renal transplantation enables better use and selection of immunosuppression with reduced adverse effects and, eventually, successful treatment of the kidney recipients. Belatacept conversion is a good and safe option in patients with deteriorating renal function attributed to CNI nephrotoxicity.

Inhibition effect of epigallocatechin-3-gallate on the pharmacokinetics of calcineurin inhibitors, tacrolimus, and cyclosporine A, in rats

BACKGROUND

Epigallocatechin-3-gallate (EGCG) is the most biologically active catechin of green tea. Tacrolimus (TAC) and cyclosporine A (CsA) are immunosuppressive agents commonly used in clinical organ transplantation. The present study investigated the effect of EGCG on the pharmacokinetics of TAC and CsA in rats and its underlying mechanisms.

RESEARCH DESIGN AND METHODS

Either TAC or CsA was administered to rats intravenously or orally with or without concomitant EGCG. Polymerase Chain Reaction and Western Blot were used to determine the effect of EGCG on drug-metabolizing enzymes (DMEs), drug transporters (DTs) and nuclear receptors (NRs).

RESULTS

The C_max and AUC of TAC were reduced, and V/F and CL/F of TAC were enhanced after co-administration of EGCG. EGCG increased the Cmax, AUC of CsA at 3 ~ 30 mg∙kg-1 dosages, while decreased those parameters at the dosage of 100 mg∙kg-1. EGCG inhibited the mRNA and protein expressions of DMEs and DTs, such as CYP3A1, A2, UGT1A1, Mdr1 and Mrp2, but upregulated the expressions of Car, Pxr and Fxr.

CONCLUSIONS

These results revealed consumption of high dose EGCG may cause a significant alteration in pharmacokinetics of TAC and distribution/elimination profiles of CsA through the regulation of DMEs, DTs and NRs.

Coenzyme Q10 alleviates tacrolimus-induced mitochondrial dysfunction in kidney

The major side effect of tacrolimus (Tac) is nephrotoxicity. We studied whether supplementation of coenzyme Q₁₀, (CoQ₁₀) a potent antioxidant, can reduce Tac-induced nephrotoxicity via improving mitochondrial function. In an in vitro study, CoQ₁₀ reduced the production of Tac-induced mitochondrial reactive oxygen species and abolished the loss of mitochondrial membrane potential in proximal tubular cell line. Assessment of mitochondrial function revealed that CoQ₁₀ decreased oxygen consumption and mitochondrial respiration rate increased by Tac, suggesting improvement of mitochondrial function to synthesize ATP with CoQ₁₀ treatment. The effect of the CoQ₁₀ in vitro study was observed in an experimental model of chronic Tac-induced nephropathy. CoQ₁₀ attenuated Tac-induced oxidative stress and was accompanied by function and histologic improvement. On electron microscopy, addition of CoQ₁₀ increased not only the number but also the volume of mitochondria compared with Tac treatment only. Our data indicate that CoQ₁₀ improves Tac-induced mitochondrial dysfunction in kidney. Supplementary CoQ₁₀ treatment may be a promising approach to reduce Tac-induced nephrotoxicity.-Yu, J. H., Lim, S. W., Luo, K., Cui, S., Quan, Y., Shin, Y. J., Lee, K. E., Kim, H. L., Ko, E. J., Chung, B. H., Kim, J. H., Chung, S. J., Yang, C. W. Coenzyme Q₁₀ alleviates tacrolimus-induced mitochondrial dysfunction in kidney.

Immunosuppressant drug tacrolimus induced mitochondrial nephrotoxicity, modified PCNA and Bcl-2 expression attenuated by Ocimum basilicum L. in CD1 mice

Tacrolimus (TAC) is used sporadically as an immunosuppressive agent for organ transplantation, but its clinical used is limited due to its marked nephrotoxicity. Ocimum basilicum L. (Lamiaceae) (OB) had been shown to possess antioxidant, anti-inflammatory and nephroprotective activity, and effective at improving renal inflammation and glomerular. In our study, we aim to evaluate the efficacy of the OB against TAC-induced mitochondrial nephrotoxicity in CD1 mice. Mice were randomly divided into four groups. Group 1 (control group); administered orally with normal saline (1 mL/kg) for two weeks; Group 2 (OB extract treated-group) (500 mg/kg b.wt) gavaged once/day for two weeks; Group 3 (TAC-treated group) (3 mg/kg b.wt, administered ip once a day for two weeks); and Group 4; (TAC plus OB extract treated-group). Tacrolimus-induced nephrotoxicity was assessed biochemically and histopathologically. The OB extract was high in phenolic content (50.3 mg/g of gallic acid equivalent), total flavonoids (14.5 mg/g CE equivalent). The potential antioxidant efficacy of the extract (IC50) was 24.5 μg/mL. OB pretreatment significantly improved the TAC-induced changes in biochemical markers of nephrotoxicity for instance blood urea nitrogen (BUN), creatinine, total protein, and albumin (P < 0.01, when compared with TAC treated group). Also, it significantly restored the increase activities of TBARS, protein carbonyl (PC) (P < 0.001, when compared to healthy control group) and decreased activities of nonprotein thiol (NP-SH) levels, Mn-superoxide dismutase (Mn-SOD) and glutathione peroxidase (GPx) antioxidants of mitochondria. The nephroprotective efficacy of the OB leaves extract was further evident by histopathological analysis together with the PCNA-ir and Bcl2. The upshot of the present study revealed that the OB possessed significant antioxidant and nephroprotective activity and had a preventive effect on the biochemical alterations and histological changes in TAC-treated mice.

Protective effect of ginsenoside Rb1 against tacrolimus-induced apoptosis in renal proximal tubular LLC-PK1 cells

Background

The aim of the present study was to evaluate the potential protective effects of six ginsenosides (Rb1, Rb2, Rc, Rd, Rg1, and Rg3) isolated from Panax ginseng against tacrolimus (FK506)-induced apoptosis in renal proximal tubular LLC-PK1 cells.

Methods

LLC-PK1 cells were treated with FK506 and ginsenosides, and cell viability was measured. Protein expressions of mitogen-activated protein kinases, caspase-3, and kidney injury molecule-1 (KIM-1) were evaluated by Western blotting analyses. The number of apoptotic cells was measured using an image-based cytometric assay.

Results

Reduction in cell viability by 60μM FK506 was ameliorated significantly by cotreatment with ginsenosides Rg1 and Rb1. The phosphorylation of p38, extracellular signal-regulated kinases, and KIM-1, and cleavage of caspase-3, increased markedly in LLC-PK1 cells treated with FK506 and significantly decreased after cotreatment with ginsenoside Rb1. The number of apoptotic cells decreased by 6.0% after cotreatment with ginsenoside Rb1 (10μM and 50μM).

Conclusion

The antiapoptotic effects of ginsenoside Rb1 on FK506-induced apoptosis were mediated by the inhibition of mitogen-activated protein kinases and caspase activation.

Protective effects of green tea and its main constituents against natural and chemical toxins: A comprehensive review

Toxins are natural or chemical poisonous substances with severe side effects on health. Humans are generally exposed by widespread toxic contaminations via air, soil, water, food, fruits and vegetables. Determining a critical antidote agent with extensive effects on different toxins is an ultimate goal for all toxicologists. Traditional medicine is currently perceived as a safe and natural approach against toxins. In this regard, we focused on the protective effects of green tea (Camellia sinensis) and its main components such as catechin, epicatechin, epicatechin gallate, gallocatechin, epigallocatechin and epigallocatechin gallate as a principal source of antioxidants against both natural and chemical toxins. This literate review demonstrates that protective effects of green tea and its constituents were mainly attributed to their anti-oxidative, radical scavenging, chelating, anti-apoptotic properties and modulating inflammatory responses. Although, some studies reveal they have protective effects by increasing toxin metabolism and neutralizing PLA₂, proteases, hyaluronidase and l-amino acid oxidase enzymes.

Protective effect of Korean Red Ginseng against FK506-induced damage in LLC-PK1 cells

BACKGROUND

Compound FK506 is an immunosuppressant agent that is frequently used to prevent rejection of solid organs upon transplant. However, nephrotoxicity due to apoptosis and inflammatory response mediated by FK506 limit its usefulness. In this study, the protective effect of Korean Red Ginseng (KRG) against FK506-induced damage in LLC-PK1 pig kidney epithelial cells was investigated.

METHODS

LLC-PK1 cells were exposed to FK506 with KRG and cell viability was measured. Western blotting and RT-PCR analyses evaluated protein expression of MAPKs, caspase-3, and KIM-1. TLR-4 gene expression was assessed. Caspase-3 activities were also determined. The number of apoptotic cells was measured using an image-based cytometric assay.

RESULTS

The reduction in LLC-PK1 cell viability by 60μM FK506 was recovered by KRG cotreatment in a dose-dependent manner. The phosphorylation of p38, p44/42 MAPKs (ERK), KIM-1, cleaved caspase-3, and TLR-4 mRNA expression was increased markedly in LLC-PK1 cells treated with 60μM FK506. However, with the exception of p-ERK, elevated levels of p-p38, KIM-1, cleaved caspase-3, and TLR-4 mRNA expression were significantly decreased after cotreatment with KRG. Activity level of caspase-3 was also attenuated by KRG cotreatment. Moreover, image-based cytometric assay showed that apoptotic cell death was increased by 60μM FK506 treatment, whereas it was decreased after cotreatment with KRG.

CONCLUSION

Taken together, these results suggest that the molecular mechanism of KRG in the FK506-induced nephrotoxicity may lead to the development of an adjuvant for the inhibition of adverse effect FK506 in the kidney.